@c -*-texinfo-*-
@c This is part of the GNU Emacs Lisp Reference Manual.
-@c Copyright (C) 1990-1995, 1998-1999, 2001-2011
+@c Copyright (C) 1990-1995, 1998-1999, 2001-2012
@c Free Software Foundation, Inc.
@c See the file elisp.texi for copying conditions.
@setfilename ../../info/minibuf
@cindex minibuffer history
@cindex history list
- A @dfn{minibuffer history list} records previous minibuffer inputs so
-the user can reuse them conveniently. A history list is actually a
-symbol, not a list; it is a variable whose value is a list of strings
-(previous inputs), most recent first.
+ A @dfn{minibuffer history list} records previous minibuffer inputs
+so the user can reuse them conveniently. It is a variable whose value
+is a list of strings (previous inputs), most recent first.
- There are many separate history lists, used for different kinds of
-inputs. It's the Lisp programmer's job to specify the right history
-list for each use of the minibuffer.
+ There are many separate minibuffer history lists, used for different
+kinds of inputs. It's the Lisp programmer's job to specify the right
+history list for each use of the minibuffer.
- You specify the history list with the optional @var{hist} argument
-to either @code{read-from-minibuffer} or @code{completing-read}. Here
-are the possible values for it:
+ You specify a minibuffer history list with the optional @var{hist}
+argument to @code{read-from-minibuffer} or @code{completing-read}.
+Here are the possible values for it:
@table @asis
@item @var{variable}
@defun try-completion string collection &optional predicate
This function returns the longest common substring of all possible
completions of @var{string} in @var{collection}. The value of
-@var{collection} must be a list of strings or symbols, an alist, an
-obarray, a hash table, or a completion function (@pxref{Programmed
-Completion}).
+@var{collection} must be a list of strings, an alist whose keys are
+strings or symbols, an obarray, a hash table, or a completion function
+(@pxref{Programmed Completion}).
Completion compares @var{string} against each of the permissible
completions specified by @var{collection}. If no permissible
If @var{collection} is an alist (@pxref{Association Lists}), the
permissible completions are the elements of the alist that are either
-strings, symbols, or conses whose @sc{car} is a string or symbol.
+strings, or conses whose @sc{car} is a string or symbol.
Symbols are converted to strings using @code{symbol-name}. Other
elements of the alist are ignored. (Remember that in Emacs Lisp, the
elements of alists do not @emph{have} to be conses.) In particular, a
-list of strings or symbols is allowed, even though we usually do not
+list of strings is allowed, even though we usually do not
think of such lists as alists.
@cindex obarray in completion
If @var{collection} is a hash table, then the keys that are strings
are the possible completions. Other keys are ignored.
-You can also use a symbol that is a function as @var{collection}.
+You can also use a function as @var{collection}.
Then the function is solely responsible for performing completion;
@code{try-completion} returns whatever this function returns. The
function is called with three arguments: @var{string}, @var{predicate}
@code{risky-local-variable} property. @xref{File Local Variables}.
@defvar completion-ignore-case
-If the value of this variable is non-@code{nil}, Emacs does not
-consider case significant in completion. Note, however, that this
-variable is overridden by @code{read-file-name-completion-ignore-case}
-within @code{read-file-name} (@pxref{Reading File Names}), and by
-@code{read-buffer-completion-ignore-case} within @code{read-buffer}
-(@pxref{High-Level Completion}).
+If the value of this variable is non-@code{nil}, case is not
+considered significant in completion. Within @code{read-file-name},
+this variable is overridden by
+@code{read-file-name-completion-ignore-case} (@pxref{Reading File
+Names}); within @code{read-buffer}, it is overridden by
+@code{read-buffer-completion-ignore-case} (@pxref{High-Level
+Completion}).
@end defvar
@defvar completion-regexp-list
@deffn Command read-color &optional prompt convert allow-empty display
This function reads a string that is a color specification, either the
color's name or an RGB hex value such as @code{#RRRGGGBBB}. It
-prompts with @var{prompt} (default: @code{"Color (name or #R+G+B+):"})
+prompts with @var{prompt} (default: @code{"Color (name or #RGB triplet):"})
and provides completion for color names, but not for hex RGB values.
In addition to names of standard colors, completion candidates include
the foreground and background colors at point.
Valid RGB values are described in @ref{Color Names}.
-The function's return value is the color name typed by the user in the
+The function's return value is the string typed by the user in the
minibuffer. However, when called interactively or if the optional
-argument @var{convert} is non-@code{nil}, it converts the name into
-the color's RGB value and returns that value as a string. If an
-invalid color name was specified, this function signals an error,
-except that empty color names are allowed when @code{allow-empty} is
+argument @var{convert} is non-@code{nil}, it converts any input color
+name into the corresponding RGB value string and instead returns that.
+This function requires a valid color specification to be input.
+Empty color names are allowed when @code{allow-empty} is
non-@code{nil} and the user enters null input.
Interactively, or when @var{display} is non-@code{nil}, the return
graphical file dialog is platform-dependent. Here, we simply document
the behavior when using the minibuffer.
-The optional argument @var{require-match} has the same meaning as in
-@code{completing-read}. @xref{Minibuffer Completion}.
+@code{read-file-name} does not automatically expand the returned file
+name. You must call @code{expand-file-name} yourself if an absolute
+file name is required.
-@code{read-file-name} uses
-@code{minibuffer-local-filename-completion-map} as the keymap if
-@var{require-match} is @code{nil}, and uses
-@code{minibuffer-local-filename-must-match-map} if @var{require-match}
-is non-@code{nil}. @xref{Completion Commands}.
+The optional argument @var{require-match} has the same meaning as in
+@code{completing-read}. @xref{Minibuffer Completion}. If
+@var{require-match} is @code{nil}, the local keymap in the minibuffer
+is @code{minibuffer-local-filename-completion-map}; otherwise, it is
+@code{minibuffer-local-filename-must-match-map}. @xref{Completion
+Commands}.
The argument @var{directory} specifies the directory to use for
-completion of relative file names. It should be an absolute directory
+completing relative file names. It should be an absolute directory
name. If @code{insert-default-directory} is non-@code{nil},
@var{directory} is also inserted in the minibuffer as initial input.
It defaults to the current buffer's value of @code{default-directory}.
possibilities. A file name is an acceptable value if @var{predicate}
returns non-@code{nil} for it.
-@code{read-file-name} does not automatically expand file names. You
-must call @code{expand-file-name} yourself if an absolute file name is
-required.
-
-Here is an example:
+Here is an example of using @code{read-file-name}:
@example
@group
@subsection Programmed Completion
@cindex programmed completion
- Sometimes it is not possible to create an alist or an obarray
-containing all the intended possible completions. In such a case, you
-can supply your own function to compute the completion of a given
-string. This is called @dfn{programmed completion}. Emacs uses
-programmed completion when completing file names (@pxref{File Name
-Completion}), among many other cases.
+ Sometimes it is not possible or convenient to create an alist or
+an obarray containing all the intended possible completions ahead
+of time. In such a case, you can supply your own function to compute
+the completion of a given string. This is called @dfn{programmed
+completion}. Emacs uses programmed completion when completing file
+names (@pxref{File Name Completion}), among many other cases.
To use this feature, pass a function as the @var{collection}
argument to @code{completing-read}. The function
@end itemize
There are currently four methods, i.e. four flag values, one for
- each of the four different basic operations:
+each of the four different basic operations:
@itemize @bullet
@item
@item
@code{(boundaries . SUFFIX)} specifies @code{completion-boundaries}.
The function should return a value of the form @code{(boundaries
-START . END)} where START is the position of the beginning boundary in
+START . END)} where START is the position of the beginning boundary
in the string to complete, and END is the position of the end boundary
in SUFFIX.
@end itemize
- It would be consistent and clean for completion functions to allow
-lambda expressions (lists that are functions) as well as function
-symbols as @var{collection}, but this is impossible. Lists as
-completion tables already have other meanings, and it would be
-unreliable to treat one differently just because it is also a possible
-function. So you must arrange for any function you wish to use for
-completion to be encapsulated in a symbol.
-
@defun completion-table-dynamic function
This function is a convenient way to write a function that can act as
programmed completion function. The argument @var{function} should be